JP5551920B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly to a power feeding structure to a semiconductor element.

  A semiconductor device on which an electronic component such as a semiconductor element is mounted is required to withstand a heat cycle caused by repeated operations, to maintain electrical connection and insulation, and to stably support the component. In particular, semiconductor devices that handle high power, such as semiconductor modules including power semiconductor elements (power semiconductor elements) such as IGBTs (insulated gate bipolar transistors), it is important to endure high heat dissipation characteristics and repeated thermal cycles. When cracks occur in the solder of the joint portion of the power semiconductor element due to repeated thermal cycles, the thermal resistance and electrical resistance increase, and when further deteriorated, the breakdown proceeds at an accelerated rate due to heat generation, There is a possibility that the function of the apparatus may not be exhibited.

  Patent Document 1 discloses a semiconductor device having an electrode member and a semiconductor element mounted using the electrode member. The electrode member is composed of an insulating support plate (power feeding plate) having a plurality of through holes and a plurality of conductor posts (power feeding posts) arranged in each through hole. The conductor post is bonded to the electrode of the semiconductor element. According to the technique of Patent Document 1, by joining a semiconductor element using the above electrode member having a plurality of conductor posts on one electrode, compared to the case of using one conductor post on one electrode, Thermal stress applied to the interface between the metal post and the semiconductor element is reduced. Therefore, even if the difference in coefficient of thermal expansion between the metal post and the semiconductor element is large, the connection reliability of the semiconductor element can be improved.

  Patent Document 2 discloses a semiconductor device having a support plate (power feeding plate) made of, for example, a glass epoxy resin substrate, and a columnar conductor (conductor post). According to the technique of Patent Document 2, the reliability of electrical conduction and the heat cycle durability related to thermal conductivity are improved.

JP 2006-237429 A JP 2009-64908 A

  The IGBT module is required to pass a large current through the conductor post, and the larger the current that can be passed (hereinafter referred to as allowable current), the higher the performance of the module. However, when a large current is passed through the conductor post, the joint between the conductor post and the support plate (wiring board) generates heat, and if further deteriorated, the joint may be broken (disconnected). This is because the conductor post and the support plate are joined using a material having a low melting point compared to the electrode of the conductor post or the support plate (hereinafter referred to as a low melting point material), for example, solder or silver solder. it is conceivable that. That is, the conductor post and the support plate are often joined by once melting the low melting point material and then curing it again. Usually, since the resistance of the low melting point material used for such joining is relatively high, when a large current is passed through the conductor post, heat is generated faster than the conductor post and the electrode of the support plate. When heat is generated, the electrical resistance further increases, so that the temperature rises at an accelerated rate. As a result, it is considered that the melted portion is remelted during energization and the joint portion is broken.

  Under such circumstances, the allowable current of the IGBT module is usually 10 amperes / piece or less. In order to increase the allowable current, it has been studied to increase the number of conductor posts and the number of electrodes of the support plate. However, this method is disadvantageous in terms of cost.

  Furthermore, in recent years, power elements capable of flowing a large current even when the element itself is small have been developed, and thereby the amount of heat generated is high. The IGBT element material itself, SiC (silicon carbide) based element has been developed in addition to the conventional Si (silicon) based element, and the conventional maximum temperature reached 250 ° C to 350 ° C compared to 150 ° C to 180 ° C. Some devices have also appeared.

  In a semiconductor device using such a power element, the power element itself flows at a high current and operates at a high temperature. However, if the allowable current at the interface between the conductor post and the electrode of the support plate is small, the power element can perform sufficiently. The problem of being unable to do so can arise.

  An object of the present invention is to provide a semiconductor device having a large allowable current and a method for manufacturing the same.

A semiconductor device according to a first aspect of the present invention includes a support plate in which a cylindrical hole is formed, a conductor is formed on a wall surface of the hole, a power semiconductor element, and a first end at one end. And a conductor post made of a columnar conductor having a second end at the other end, and the end face shape of the first end part and the opening shape of the hole are non-similar, and the side face of the conductor post The fixing surface of the hole wall surface with the conductor includes two or more surfaces having substantially the same area, these surfaces are arranged substantially symmetrically, and the second end portion of the conductor post is used for the power connected to the semiconductor element, the side surface of the conductor posts, in the first end portion side of the second end portion, partially secured to the conductor of the hole wall is deformed by the pressing of the conductor posts Yes.

  It is preferable that a contact area between the conductor post and the conductor on the hole wall surface is at least 50% or more of an area of a cross section perpendicular to the axial direction of the conductor post.

  A conductor layer may be formed on at least one main surface of the support plate, and the side surface of the conductor post may be in contact with the conductor layer of the main surface.

  The contact area between the side surface of the conductor post and the conductor layer is preferably at least 15% or more of the area of a cross section perpendicular to the axial direction of the conductor post.

The end surface shape of the first end, yen elliptic, rectangular, regular polygon, positive polygonal star, cross, cosmos form, or is preferably two or more of which are bound form.

  The main component of the conductor post is preferably copper, silver, gold, or aluminum.

  The conductor post has a columnar conductor composed mainly of copper, silver, gold, or aluminum, and a coating film made of chromium, nickel, palladium, titanium, or platinum formed on the surface of the columnar conductor. It is good also as a structure.

  The thickness of the coating film is preferably 0.5 μm to 10 μm.

The semiconductor device may further include a heat radiating plate having a conductor layer on at least the support plate side main surface, and at least one electrode of the power semiconductor element may be fixed to the conductor layer of the heat radiating plate. Good.

The method of manufacturing a semiconductor device according to the second aspect of the present invention includes forming a cylindrical hole in a support plate, forming a conductor on a wall surface of the hole, and having an end surface shape that is not different from the opening shape of the hole. A first end of a conductor post having a similar relationship is fitted into the hole, and the first end and the conductor on the hole wall surface are partially fixed; and the first end of the conductor post a second end opposite the section, seen including a connecting to a power semiconductor device, and the fixation surface between the conductor side with the hole wall surface of the conductor posts 2 of substantially the same area The above surfaces are included, and these surfaces are arranged substantially symmetrically .

The width of the first end portion of the prefrontal Symbol fitting is different from the width of the corresponding portion of the bore, it is preferably greater by 5% to 75% of the dimensions of the conductor thickness of the hole wall.

  According to the present invention, it is possible to provide a semiconductor device having a large allowable current and a manufacturing method thereof.

It is a figure showing a semiconductor device concerning an embodiment of the present invention. It is AA sectional drawing of FIG. It is sectional drawing which shows the connection structure of a conductor post and a support plate. It is a top view which shows the structure of a conductor post. It is sectional drawing which shows the junction part of the conductor post and the wall surface of the hole of a support plate. It is a flowchart which shows the content and procedure of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a figure which shows the relationship between the end surface shape of a 1st edge part, and the opening shape of a hole. It is a figure which shows an example of the semiconductor device containing an IGBT element and an FWD element. It is AA sectional drawing of FIG. It is a figure which shows an example of the coated conductor post. It is a figure which shows the example by which a conductor post is inserted in a bottomed hole. It is a figure which shows the example which provided the electroconductive material for connecting a conductor post in the 2nd surface side of the support plate. It is a figure which shows the regular tetragon as another example of the shape of a conductor post. It is a figure which shows the regular hexagon as another example of the shape of a conductor post. It is a figure which shows the regular octagon as another example of the shape of a conductor post. It is a figure which shows the ellipse as another example of the shape of a conductor post. It is a figure which shows the cross shape as another example of the shape of a conductor post. It is a figure which shows the regular polygon star shape as another example of the shape of a conductor post. It is a figure which shows the cosmos shape as another example of the shape of a conductor post. It is sectional drawing which shows the junction part of a square-shaped conductor post and the wall surface of a circular hole. It is sectional drawing which shows the junction part of a cross-shaped conductor post and the wall surface of a circular hole. It is sectional drawing which shows the junction part of a cosmos-type conductor post and the wall surface of a circular hole. It is a figure which shows the straight form as another example of the shape of a conductor post. It is a figure which shows the taper shape as another example of the shape of a conductor post. It is a figure which shows the barrel shape as another example of the shape of a conductor post. It is a figure which shows the hourglass shape as another example of the shape of a conductor post. It is a figure which shows another example of the shape of the collar part of a stepped post. It is a figure which shows an example of the conductor post which has a some collar part. It is a figure which shows an example of the conductor post which has a hollow. It is a figure which shows an example which adheres in the state which the conductor post stopped in the hole. It is a figure which shows an example fixed in the state which the conductor post penetrated the hole. It is a figure which shows an example to which the curved surface of a conductor post and the wall surface of a hole adhere. It is a top view which shows the more practical shape of a conductor post. It is a side view which shows the more practical shape of a conductor post. FIG. 6 is a diagram for explaining a first step of the method for manufacturing a support plate according to the first embodiment. It is a figure for demonstrating the 2nd process after the process of FIG. 23A. It is a figure for demonstrating the 3rd process after the process of FIG. 23B. It is a figure for demonstrating the 4th process after the process of FIG. 23C. It is a figure for demonstrating the 5th process after the process of FIG. 23D. It is a figure for demonstrating the 1st process of the method of inserting a conductor post in the hole of a support plate in Example 1. FIG. It is a figure for demonstrating the 2nd process after the process of FIG. 24A. It is a figure for demonstrating the 3rd process after the process of FIG. 24B. It is a figure for demonstrating the 4th process after the process of FIG. 24C. It is a figure for demonstrating the 5th process after the process of FIG. 24D. It is a figure which shows the state by which the conductor post which concerns on Example 1 was connected to the support plate. It is a figure for demonstrating the 1st process of coating the surface of a conductor circuit in Example 2. FIG. It is a figure for demonstrating the 2nd process after the process of FIG. 26A. It is a graph which shows the shape of a hole, the conductor of the wall surface, etc. about Examples 1-7 and Comparative Example 1. FIG. It is a graph which shows the material etc. of a conductor post about Examples 1-7 and Comparative Example 1. FIG. It is a graph which shows the adhering area (fitting area) etc. of an adhering part about Examples 1-7 and Comparative Example 1. FIG. It is a chart which shows the measurement result of allowable current about Examples 1-7 and comparative example 1.

  Hereinafter, embodiments of the present invention will be described. In the drawing, arrows Z1 and Z2 indicate the stacking direction of the wiring boards corresponding to the normal direction of the main surface (front and back surfaces) of the wiring board (that is, the thickness direction of the heat sink). On the other hand, arrows X1, X2 and Y1, Y2 respectively indicate directions perpendicular to the stacking direction (directions parallel to the main surface of the wiring board). The main surface of the wiring board is an XY plane. The side surface of the wiring board is an XZ plane or a YZ plane.

  In the embodiment, the two main surfaces facing the opposite normal directions are referred to as a first surface (a surface on the arrow Z1 side) and a second surface (a surface on the arrow Z2 side). That is, the main surface opposite to the first surface is the second surface, and the main surface opposite to the second surface is the first surface.

  Regarding the conductor post, the axis is a line parallel to the Z direction (insertion direction) and passing through the center of the conductor post. That is, the Z direction corresponds to the axial direction. A cross section (XY plane) orthogonal to the axial direction is referred to as a cross section. A cross section (XZ plane or YZ plane) parallel to the axial direction is referred to as a vertical cross section.

  In addition, a layer including a conductor pattern that functions as a wiring of a circuit or the like is called a wiring layer. The conductor film formed on the wall surface of the through hole is called a through hole conductor. In addition to the conductor pattern, the wiring layer may include a land of a through-hole conductor. The “hole” includes not only a through hole but also a non-through hole. When a non-through hole is referred to as a “wall surface” of the hole, the “wall surface” includes the bottom surface as well as the side surface. Unless otherwise specified, the “width” of a hole or a column (projection) means a diameter in the case of a circle and means √ (4 × cross-sectional area / π) otherwise. When a conductor or the like is formed on the wall surface of the hole, the width of the hole is reduced by the thickness unless otherwise specified. When the hole or column (projection) is tapered, the value, average value, maximum value, etc. of the corresponding parts are compared to determine whether or not the “width” of two or more holes or protrusions match. be able to. “Insertion” includes not only inserting a member sufficiently thin compared to the hole diameter into the hole but also inserting or screwing the member into the hole.

  1 and 2 show a semiconductor device 101 of this embodiment. FIG. 1 is an exploded view of the semiconductor device 101. However, for convenience of explanation, illustration of some elements is omitted in FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG.

  The semiconductor device 101 includes a semiconductor element 10, a heat dissipation plate 20, a connection substrate 50, and external connection terminals 61 to 64. The connection substrate 50 includes a support plate 30 and conductor posts 40.

  The semiconductor element 10 is made of, for example, an IGBT element. However, the present invention is not limited to this, and the semiconductor element 10 may be another power semiconductor element such as a GTO (gate turn-off thyristor) used for a switching power supply, an inverter, or the like. Moreover, it is not limited to the power semiconductor element, and the type of the semiconductor element 10 is arbitrary.

  The heat sink 20 is made of, for example, an insulating ceramic plate, a heat resistant resin, or an insulated metal plate. However, it is not limited to this, The material of the heat sink 20 is arbitrary.

  An electrode 11 is provided on the second surface (back surface) of the semiconductor element 10. The electrode 11 is, for example, a collector electrode. On the other hand, electrodes 12, 13, and 14 are provided on the first surface (front surface) of the semiconductor element 10. The electrode 12 is, for example, a gate electrode, the electrode 13 is, for example, an electrode of various sensors, and the electrode 14 is, for example, an emitter electrode.

  A conductive electrode 21 (conductor layer) is formed on the first surface (support plate side main surface) of the heat radiating plate 20. The electrode 21 is electrically connected to the electrode 11 through the conductive material 71a. Thereby, the semiconductor element 10 is fixed to the heat sink 20. The conductive material 71a is made of, for example, a solder material such as solder or silver solder, or a conductive paste. The property of the conductive material 71a is changed (for example, cured) by, for example, temperature or pressure. By utilizing such a property change, the electrode 11 and the electrode 21 can be bonded. Hereinafter, the portion connected by the conductive material 71a is referred to as a first connection portion.

  The support plate 30 is a wiring board composed of an insulating substrate 30a, conductor circuits 31, 32, and a conductor 33 (through-hole conductor). The conductor circuit 31 is formed on the second surface (lower surface) of the insulating substrate 30a, and the conductor circuit 32 is formed on the first surface (upper surface) of the insulating substrate 30a. The support plate 30 is formed with a plurality of holes 30b (number corresponding to the conductor posts 40). The hole 30b is, for example, a through hole (through hole). A conductor 33 is formed on the wall surface of the hole 30b. The hole 30b may be a bottomed hole (see FIG. 11 described later). The conductor circuits 31, 32 and the conductor 33 are made of, for example, copper. Copper is widely used as a printed wiring board and is easily available. However, these materials are not limited to copper, and are arbitrary as long as they are conductive materials.

  The conductor post 40 is a columnar conductor made of a metal such as copper. The conductor post 40 includes a gate post G connected to the electrode 12 (gate electrode), a sensor post S connected to the electrode 13 (sensor electrode), an emitter post E connected to the electrode 14 (emitter electrode), Are distinguished. The gate post G includes, for example, two conductor posts 40, the sensor post S includes, for example, one conductor post 40, and the emitter post E includes, for example, 15 (3 × 5) conductor posts 40. included.

  Each of the conductor posts 40 included in the gate post G, sensor post S, and emitter post E includes a first column part 41 and a second column as shown in FIG. 3 (sectional view) and FIG. 4 (plan view). It has the part 42 and the collar part 43. The collar portion 43 functions as a stopper. That is, when the conductor post 40 is inserted into the hole 30b, excessive insertion is prevented by the flange portion 43.

  The conductor post 40 has a first end 41a at one end and a second end 42a at the other end. The first end portion 41a is an end portion on the arrow Z1 side of the first column portion 41, and the second end portion 42a is an end portion on the arrow Z2 side of the second column portion 42 (opposite to the first end portion 41a). Side end). Each shape of the 1st pillar part 41, the 2nd pillar part 42, and the collar part 43 is a cylinder. The end face shape of the first end portion 41a and the opening shape of the hole 30b are both circles, and both are in a similar relationship (see FIG. 7 described later). However, it is not limited to this, These shapes are arbitrary (refer below-mentioned FIG. 13A-FIG. 20).

  A part of the conductor post 40 (first column part 41) is inserted into the hole 30b from the first end 41a side. A second end portion 42a of the conductor post 40 is connected to each of the electrodes 12, 13, and 14.

  FIG. 5 is a cross-sectional view (XY plane) showing a joint portion between the conductor post 40 and the wall surface (conductor 33) of the hole 30b. As shown in FIG. 5, the side surface of the conductor post 40 is fixed to the conductor 33 on the first end portion 41 a side (first column portion 41) with respect to the second end portion 42 a. In addition, the conductor 33 is deformed by the pressing of the conductor post 40 (pressure due to insertion). That is, the conductor post 40 and the conductor 33 are directly fixed. For this reason, the material which melts at a low temperature such as solder and silver solder can be excluded from the interface, and the conductivity can be improved. Further, on the fitting surface (fixed surface), at least a part of the conductor post 40 is fixed while being deformed by a mechanical force, so that an inhibitory substance (on the surface of the conductor post 40, the wall surface of the hole 30b, etc.) Oxygen etc. can be eliminated to increase the conductivity.

  In addition, since the end face shape of the first end portion 41 a and the opening shape of the hole 30 b are similar to each other, the fixing face F <b> 1 (fitting face) is formed over substantially the entire circumference of the conductor post 40. Thereby, connection strength improves.

  Here, the contact area (fixed area) between the conductor post 40 and the wall surface (conductor 33) of the hole 30b is preferably at least 50% of the area of the cross section of the conductor post 40. This is because the inventors have discovered that if it is less than 50%, heat is generated locally due to an increase in electrical resistance, oxidation is promoted, and there is a concern that the electrical resistance becomes high.

  Further, as shown in FIG. 3, the side surface of the conductor post 40 is in contact with the conductor circuits 31 and 32. The heat transfer from the conductor post 40 to the conductor circuits 31 and 32 is smooth, and the current flows smoothly. Such an effect becomes prominent when the contact area (total) between the conductor post 40 and the conductor circuits 31 and 32 is 15% or more of the area of the cross section of the conductor post 40, and more prominent when it is 25% or more. Therefore, it is preferable to set the contact area in such a range.

  The electrodes 12, 13, and 14 and the second end portion 42a of the conductor post 40 are electrically connected via conductive materials 72a, 72b, and 72c, respectively. The conductive materials 72a to 72c are made of, for example, a solder material such as solder or silver solder, or a conductive paste. The conductive materials 72a to 72c have adhesiveness like the conductive material 71a. Hereinafter, the portion connected by the conductive materials 72a to 72c is referred to as a second connection portion.

  The external connection terminal 61 is connected to the electrode 21, and the external connection terminals 62 to 64 are connected to the conductor circuit 32. The external connection terminal 61 and the electrode 21 are electrically connected via a conductive material 71b. The external connection terminals 62, 63, 64 and the conductor circuit 32 are electrically connected through conductive materials 73a, 73b, 73c, respectively. As a result, the external connection terminal 62 and the electrode 12, the external connection terminal 63 and the electrode 13, and the external connection terminal 64 and the electrode 14 are electrically connected to each other. The conductive materials 71b and 73a to 73c are made of, for example, a solder material such as solder or silver solder, or a conductive paste. The conductive materials 71b and 73a to 73c have adhesiveness like the conductive material 71a.

  As a material of the conductor post 40, it is effective to use, for example, a metal or alloy mainly composed of copper, aluminum, silver, or gold. Among them, a metal or alloy mainly composed of copper or aluminum is particularly effective. In addition, an aluminum or copper alloy having an electrical resistivity with respect to copper exceeding 50% is also effective. These materials are easily deformed by mechanical stress and easily form a fixing surface. Moreover, in these materials, since the rate of change in electrical resistance with respect to temperature rise is small, it is easy to maintain low electrical resistance even when the temperature rises.

  The semiconductor device 101 is manufactured by a procedure as shown in FIG. 6, for example.

  In step S11, a hole 30b is formed at the mounting position of the conductor post 40 of the insulating substrate 30a. The hole 30b can be formed by, for example, a drill or a laser.

  In the subsequent step S12, a conductor is formed on the insulating substrate 30a. That is, for example, by plating, a conductor layer is formed on both surfaces of the insulating substrate 30a, and a conductor 33 is formed on the wall surface of the hole 30b. Thereafter, the conductor layers on both sides are patterned to form conductor circuits 31 and 32. This patterning time may be before or after step S13. In addition, the formation method of a conductor layer is arbitrary. For example, a metal foil (for example, copper foil) prepared separately may be bonded to the insulating substrate 30a. For example, the conductor layer and the conductor 33 may be formed by plating after electroless plating, sputtering, or vapor deposition. However, when a conductor is also formed on the wall surface of the hole 30b, plating is preferable. With plating, a conductor can be easily formed on the wall surface of the hole 30b.

  In subsequent step S13, the conductor post 40 is fitted into the hole 30b from the first end 41a side. Thereby, the connection substrate 50 is completed.

  As shown in FIG. 7, the end face shape of the first end portion 41a and the opening shape of the hole 30b are in a similar relationship. Before the conductor post 40 is inserted (inserted) into the hole 30b, the width (diameter) of the first end 41a on the side to be inserted is the corresponding portion of the hole 30b (diameter after the conductor 33 is formed). Greater than width. For this reason, the wall surface of the hole 30b (more specifically, the conductor 33) receives the pressure from the conductor post 40 and deforms due to the insertion of the conductor post 40. The width (diameter) of the first end portion 41a before insertion is larger than the width of the corresponding portion of the hole 30b by a dimension of 1% to 75% of the thickness of the conductor 33 (d in FIG. 3). In particular, in the case of a similar shape, it is more preferable that the size is larger by 1% to 50%. If it is less than 1%, the size of the conductor post 40 and the size of the hole 30b are substantially equal, and the amount of deformation of the conductor post 40 is difficult to be secured. In addition, it becomes difficult to secure a sufficient fixing area, and there is a possibility that a corrosive substance such as oxygen may be caught in the fixing portion. On the other hand, if it exceeds 75%, the conductor film (conductor 33) formed on the wall surface of the hole 30b is mechanically broken, and it may not function as an original connection pin. In this sense, the above 1% to 75% is a preferable range.

  In the case of similarity, the entire circumference of the conductor post 40 is connected (fixed) to the hole 30b. This is preferable for increasing the connection strength, but if the width of the first end portion 41a fitted to the hole 30b is larger than 50%, the conductor layer (conductor 33) formed on the wall surface of the hole 30b is mechanically formed. Or may be destroyed by thermal stress. In this sense, in the case of a similar shape, the above 1% to 50% is a more preferable range.

  In addition, when manufacturing the conductor post 40 which has copper or aluminum as a main component, it is preferable to perform the heat processing by heating annealing, such as annealing, previously or in a manufacturing stage.

  In subsequent step S <b> 14, the semiconductor element 10 is mounted (connected) to the heat sink 20.

  In subsequent step S <b> 15, the semiconductor element 10 is mounted (connected) to the connection substrate 50.

  Thereafter, the external connection terminals 61 to 64 are connected to complete the semiconductor device 101. Details of steps S11 to S15 will be described in Examples 1 and 2 described later. The order of these steps can be changed as appropriate.

  The present invention is not limited to the above embodiment. For example, the present invention can be modified as follows.

  A plurality of semiconductor elements may be used. A plurality of different types of semiconductor elements may be used. For example, as in the semiconductor device 102 shown in FIG. 8 (a figure corresponding to FIG. 1) and FIG. 9 (a figure corresponding to FIG. 2), in addition to the semiconductor element 10 made of an IGBT element, a semiconductor element 10a made of an FWD element is provided. You may arrange. The semiconductor element 10a is mounted in parallel between the emitter and collector of the semiconductor element 10, for example. The semiconductor element 10a has an electrode 11a on the second surface (back surface) and an electrode 12a on the first surface (front surface).

  In this case, the conductor post 40 is distinguished not only from the gate post G, the sensor post S, and the emitter post E, but also to the FWD post F connected to the electrode 12a (FWD electrode). The FWD post F includes, for example, four (2 × 2) conductor posts 40. The electrode 11a is electrically connected to the electrode 21 through the conductive material 71c. A portion connected by the conductive material 71c is also included in the first connection portion described above. The electrode 12a is electrically connected to the second end portion 42a of the conductor post 40 via the conductive material 72d. A portion connected by the conductive material 72d is also included in the above-described second connection portion. The external connection terminal 65 is electrically connected to the conductor circuit 32 via the conductive material 73d. Thereby, the external connection terminal 65 and the electrode 12a are electrically connected to each other. The conductive materials 71c, 72d, and 73d are made of, for example, a solder material such as solder or silver solder, or a conductive paste. The conductive materials 71c, 72d, and 73d have adhesiveness like the conductive material 71a.

  Thus, by arranging the FWD element in parallel with the IGBT element, noise (reverse current) generated by switching of the IGBT element can be reduced.

  The conductor post 40 may be coated in a manner that does not affect the overall hardness. For example, as shown in FIG. 10, the conductor post 40 may be composed of a columnar conductor 40a and a coating film 40b, and the columnar conductor 40a may be covered with a coating film 40b having high hardness. As a material for the columnar conductor 40a, a material mainly composed of copper, silver, gold, or aluminum is effective. For example, chromium, nickel, palladium, titanium, or platinum is effective as the material of the coating film 40b. These materials are resistant to corrosive substances such as oxygen and can suppress changes in resistance at the connection interface even when heat is generated. The thickness of the coating film 40b is preferably 0.5 to 10 μm. When it is thinner than 0.5 μm, resistance to oxidation and corrosion is reduced. On the other hand, if it is thicker than 10 μm, the metal is a relatively hard material, and thus there is a risk of inhibiting the deformation of the columnar conductor 40a. In this sense, the above 0.5 to 10 μm is a preferable range. The coating film 40b may be coated with plating or sputtering after the columnar conductor 40a is fitted (fixed) to the hole 30b.

  As shown in FIG. 11, the hole 30b may be a bottomed hole. The conductor 33 may be formed on the entire wall surface of the hole 30b or may be formed only on the side surface of the hole 30b.

  As shown in FIG. 12, a conductive material 74 may be provided on the second surface side of the support plate 30 to increase the connection strength between the support plate 30 and the conductor post 40. The conductive material 74 is made of, for example, a solder material such as solder or silver solder, or a conductive paste. The conductive material 74 has adhesiveness like the conductive material 71a and the like.

  The shape of the conductor post 40 is not limited to a cylinder, but is arbitrary. For example, the end surface of the conductor post 40 (the end surface on the first end portion 41a side or the second end portion 42a side), the first column portion 41 (particularly the first end portion 41a), the second column portion 42 (particularly the second end portion). 42a) or the shape of the cross section (XY plane) of the collar portion 43 is not limited to a circle (perfect circle) and is arbitrary. The shape of these surfaces may be a regular polygon such as a regular square, a regular hexagon, or a regular octagon as shown in FIGS. 13A, 13B, and 13C, for example. In addition, the shape of each surface may be a U shape, an L shape, a V shape, or the like. The corner shape such as a polygon, U shape, L shape, or V shape is arbitrary, and may be, for example, a right angle, an acute angle, an obtuse angle, or a rounded shape. However, in order to prevent concentration of thermal stress, it is preferable that the corners are rounded.

  Moreover, as shown in FIG. 14, the shape of each said surface may be an ellipse. Moreover, a rectangle, a triangle, etc. may be sufficient. However, these shapes are disadvantageous in that they have anisotropy.

  The circle, ellipse, and regular polygon have the advantage of being easily similar to the shape of the hole.

  Further, as shown in FIGS. 15A to 15C, a straight line is drawn radially from the center, such as a cross shape (see, for example, FIG. 15A), a regular polygon star shape (see, for example, FIG. 15B), or a cosmos shape (see, for example, FIG. 15C). A shape (a shape in which a plurality of blades are arranged radially) is also effective as the shape of each surface. The conductor post 40 having such a shape is suitable for insertion into the hole 30b when the shape of the hole 30b is a simple shape such as a cylinder.

  In addition, a shape obtained by combining (combining) the above shapes can also be used. One of these shapes may be the opening shape of the hole 30b. The end face shape of the first end portion 41a and the opening shape of the hole 30b may be similar or dissimilar. Therefore, arbitrary shapes can be combined by selecting each shape from the shapes shown in FIGS. 13A to 15C, for example.

  However, when the end face shape of the first end portion 41a and the opening shape of the hole 30b are not similar, the width of the first end portion 41a before insertion is larger than the width of the corresponding portion of the hole 30b. It is more preferable that the conductor 33 is larger by a dimension of 5% to 75% of the thickness of the conductor 33. As described above, the range of 1% to 75% is preferable. In the case of dissimilarity, at least a part of the first end portion 41a is fixed, and there is a place where the conductor post 40 does not partially contact the conductor 33. It is difficult to ensure the area. For this reason, it is not preferable to make it smaller than 5%. In this sense, in the case of dissimilarity, the above 5% to 75% is a more preferable range.

  Moreover, it is preferable that two or more surfaces having substantially the same area are included in the fixing surface F1 between the first end portion 41a and the wall surface of the hole 30b, and these surfaces are disposed substantially symmetrically. By making the fixing surface F1 have substantially the same area, the electric resistance can be made equal, and the heat generated by making it substantially symmetric can be evenly distributed to the connecting portion. As a result, it is possible to mitigate the intensive increase in temperature.

  FIG. 16A to FIG. 16C show a joint portion of the conductor post 40 when the opening shape of the hole 30b is a circle, for example. When the first end portion 41a whose end face shape is a regular square is fitted into the hole 30b, as shown in FIG. 16A, four fixing surfaces F1 having substantially the same area are formed, and these are formed on the axis of the conductor post 40. They are arranged approximately symmetrically. Further, as shown in FIGS. 16B and 16C, the same fixing surface F1 can be obtained in the case of a cross shape or a cosmos shape. However, in the example of the cosmos shape shown in FIG. 16C, there are eight fixing surfaces F1.

  On the other hand, the shape of the vertical cross section (XZ plane or YZ plane) of the conductor post 40 is not limited to the stepped shape (see, for example, FIG. 3) and is arbitrary. For example, as shown in FIGS. 17A to 17D, the shape may be a straight shape (see, for example, FIG. 17A), a tapered shape (see, for example, FIG. 17B), a barrel shape (see, for example, FIG. 17C), or a drum shape (see, for example, FIG. 17D). ).

  The shape of the collar portion 43 is also arbitrary, and may be spherical as shown in FIG. 18, for example. The number of the collar parts 43 is also arbitrary. For example, as shown in FIG. 19, flange portions 43 (convex portions) may be provided at a plurality of locations (for example, two locations) on the side surface (circumferential surface) of the conductor post 40.

  For example, as shown in FIG. 20, a depression 44 (concave portion) may be provided on the side surface (circumferential surface) of the conductor post 40. The shape and number of the depressions 44 are arbitrary.

  The conductor post 40 fitted to the hole 30b may remain in the hole 30b as shown in FIG. 21A or may penetrate through the hole 30b as shown in FIG. 21B. Further, as shown in FIG. 21C, the side surface of the conductor post 40 having a curved surface may be fixed to the wall surface (conductor 33) of the hole 30b.

  Although the shape of the conductor post 40 is schematically shown in FIG. 3 and the like, actually, as shown in FIG. 22A (plan view) and FIG. 22B (side view), the conductor post 40 is adapted to the application. It is preferable to precisely design the shape. For example, in order to reduce weight, reduce material, etc., it is preferable to reduce the volume as much as possible by cutting unnecessary portions or making holes. Details of the shapes shown in FIGS. 22A and 22B will be described in Example 2 described later.

  The configuration of the semiconductor devices 101 and 102 and the type, performance, dimensions, material, shape, number of layers, arrangement, and the like of the components can be arbitrarily changed without departing from the spirit of the present invention.

  The manufacturing method of the present invention is not limited to the contents and order shown in the flowchart of FIG. 6, and the contents and order can be arbitrarily changed without departing from the spirit of the present invention. Moreover, you may omit the process which is not required according to a use etc.

Example 1
Hereinafter, the semiconductor device 102 (see FIGS. 8 and 9) according to the first embodiment will be described. In this example, the same elements as those shown in the above embodiment are denoted by the same reference numerals, and more detailed parameters are specified for each element.

  The semiconductor element 10 is an IGBT chip made of Si having a thickness of 0.09 mm and a size of 8 × 8 mm. The semiconductor element 10 has external connection terminals 61 to 64 as external electrodes. The external connection terminal 61 is a collector electrode having a size of 10 × 1 mm and a length of 40 mm. The external connection terminal 62 is a gate electrode having a diameter of 1 mm and a length of 29 mm. The external connection terminal 63 is an electrode of various sensors having a diameter of 1 mm and a length of 29 mm. The external connection terminal 64 is an emitter electrode having a size of 10 × 1 mm and a length of 29 mm.

  The semiconductor element 10a is a FWD chip made of Si having a thickness of 0.09 mm and a size of 2 × 2 mm. The electrodes 11a and 12a are electrodes of an FWD chip.

  The heat sink 20 is an ALN heat sink. Specifically, the heat sink 20 is made of AlN (aluminum nitride) ceramic having a thickness of 0.64 mm and a size of 14 × 12 mm. The electrode 21 bonded to one surface of the heat sink 20 has a thickness of 0.3 mm, a size of 12 × 10 mm, and contains contained elements “Fe: 0.85%, Zn: 0.12%, P: 0.03%”. It consists of a copper plate (C1940).

  The connection substrate 50 includes a support plate 30 and conductor posts 40. The support plate 30 is a wiring board having a thickness of 0.47 mm and a size of 14 × 12 mm. Further, the shape of the conductor post 40 is different from the shape shown in FIGS. 8 and 9 (see FIG. 25).

  The support plate 30 is manufactured by the following procedure. This process corresponds to steps S11 and S12 in FIG.

  First, as shown in FIG. 23A, a starting material for the support plate 30 (hereinafter referred to as a starting substrate 300) is prepared. The starting substrate 300 is an HL679 FGS substrate (manufactured by Hitachi Chemical). The starting substrate 300 includes an insulating substrate 30a and copper foils 301 and 302 laminated on both surfaces of the insulating substrate 30a. The thickness of the insulating substrate 30a is 0.2 mm, and the thickness of the copper foils 302 and 302 is 0.105 mm.

  Subsequently, as shown in FIG. 23B, a hole 30b having a diameter of 0.5 mm is formed (drilled) in the starting substrate 300 by a drill. The hole 30b is a through hole. The hole 30b is formed to face each of the electrodes 12 to 14 and 12a (pad). The number of holes 30b facing each electrode is “gate electrode: 2, sensor electrode: 1, emitter electrode: 3 × 5 = 15” for the electrodes 12 to 14 of the semiconductor element 10, and for the electrode 12a of the semiconductor element 10a. “2 × 2 = 4”. The holes 30b are arranged at the center of the electrodes 12 to 14 and 12a at a pitch of 1 mm.

  Subsequently, as shown in FIG. 23C, a chemical copper plating film 303 having a thickness of 0.1 μm is formed on the entire substrate surface by chemical copper plating (manufactured by Uemura Plating).

  Subsequently, as shown in FIG. 23D, an electrolytic copper plating film 304 having a thickness of 30 μm is formed on the entire substrate surface by electrolytic copper plating (Okuno Pharmaceutical Co., Ltd.). As a result, a conductor layer composed of three layers of the copper foil 301 or 302, the chemical copper plating film 303, and the electrolytic copper plating film 304 is formed on both surfaces of the substrate, and the conductor 33 (copper plating film) is formed in the hole 30b. The

  Subsequently, as shown in FIG. 23E, the conductor circuits 31 and 32 are formed by patterning the conductor layers formed on both sides of the substrate. Specifically, a photosensitive dry film is laminated on both surfaces of the plated substrate, and this is patterned by a photolithography technique. Thereby, a dry film having an arrangement and dimensions corresponding to the electrodes of the semiconductor elements 10 and 10a is formed. Thereafter, the conductor layer is etched with a copper chloride solution while the dry film is left on the conductor layer. Thereby, the conductor circuits 31 and 32 are formed.

  Subsequently, the substrate on which the conductor circuits 31 and 32 are formed is cut into a size of 14 × 12 mm. A dicing saw (manufactured by Tokyo Seimitsu Co., Ltd.) is used for this cutting. Thereby, the support plate 30 having a thickness of 0.47 mm is obtained.

  The conductor post 40 is inserted into the hole 30b of the support plate 30 as follows. This step is a step corresponding to step S13 in FIG.

  First, as shown in FIG. 24A, a copper plate 401 having a thickness of 0.8 mm is set in a mold (mold punch 1001, mold die 1002). The copper plate 401 is made of oxygen-free copper C1020 (manufactured by Mitsubishi Shindoh Co., Ltd.). The diameter of the mold punch 1001 is 0.45 mm.

  Subsequently, as shown in FIG. 24B, the copper plate 401 is driven with a mold punch 1001 and protruded by 0.05 mm.

  Subsequently, as shown in FIG. 24C, the protruding portion of the copper plate 401 is opposed to the hole 30b of the support plate 30, and both are brought into close contact with each other.

  Subsequently, as shown in FIG. 24D, a copper plate 401 is driven into the hole 30b using a mold punch 1001. Accordingly, as shown in FIG. 24E, the conductor post 40 penetrates the hole 30b and protrudes about 0.6 mm toward the opposite side (arrow Z2 side). Each parameter of the protruding portion of the conductor post 40 (protruding portion P1 in the drawing) is “average diameter: 0.44 mm, average protruding amount: 0.595 mm, aspect ratio: 1.352”.

In the present embodiment, the conductor post 40 is inserted (inserted) into the hole 30b of the support plate 30 from the second end portion 42a side. Thereby, the wall surface (more specifically, the conductor 33) of the hole 30b is pressed by the conductor post 40 and deformed. As a result, the conductor post 40 is fixed in a state of being engaged with the conductor 33. The fitting area (the area where the conductor post 40 and the conductor 33 on the wall surface of the hole 30b are fixed) was 0.283 mm ² . As shown in FIG. 25, the side surface S1 (circumferential surface) of the conductor post 40 and the side surface of the conductor circuit 31 are substantially in contact with each other.

  With this method, the conductor posts 40 are inserted (inserted) into all the holes 30b. As a result, the coplanarity of the conductor post 40 was 0.028 mm. Note that coplanarity means a certain degree of uniformity (uniformity) in the way the terminals of parts are arranged in the same plane.

  Subsequently, sparkle flux WF-6400 (manufactured by Senju Metal Co., Ltd.) and Eco Solder Ball SM705 (manufactured by Senju Metal Co., Ltd.) are filled in the gap between the support plate 30 and the conductor post 40 in the hole 30b. Eco solder ball SM705 is a Pb-free solder ball having a diameter of 0.45 mm and containing elements “Ag: 3%, Cu: 0.5%”.

Thereafter, the support plate 30 is passed through a reflow furnace in an N ₂ atmosphere at a speed of 60 mm / min, and the wall surface of the hole 30b and the conductor post 40 are soldered. Thereby, the connection between the support plate 30 and the conductor post 40 is reinforced. As a result, the connection board 50 is manufactured. At the time of melting the solder, the maximum temperature achieved by heating is 280 ° C. Moreover, the time heated to 240 degreeC or more is 35 minutes. And after returning to normal temperature, the said soldered board | substrate is taken out from a reflow furnace at a cooling rate of 5 degree-C / min.

  The semiconductor elements 10 and 10a are mounted (connected) to the heat sink 20 as follows. This step is a step corresponding to step S14 in FIG.

The conductive material 71a, 71c connects the electrode 11 of the semiconductor element 10, the electrode 11a of the semiconductor element 10a, and the electrode 21 of the heat sink 20 to each other. The conductive materials 71a and 71c are made of Sn solder containing the element “Ag: 3%, Cu: 0.5%”. The semiconductor elements 10 and 10a are soldered by conductive materials 71a and 71c in a reflow furnace in an N ₂ atmosphere. When the solder is melted, the maximum temperature achieved by heating is 260 ° C. Moreover, the time heated to 240 degreeC or more is 90 second.

  The semiconductor elements 10 and 10a are mounted (connected) to the connection substrate 50 as follows. This step is a step corresponding to step S15 in FIG.

  After the semiconductor elements 10 and 10a are mounted on the heat dissipation plate 20, conductive materials 72a to 72d having a thickness of 30 μm are printed on the electrodes 12 to 14 of the semiconductor element 10 and the electrodes 12a of the semiconductor element 10a. The conductive materials 72a to 72d are made of, for example, solder paste S70G (manufactured by Senju Metal Co., Ltd.). The solder paste S70G is Sn solder containing the element “Ag: 3%, Cu: 0.5%”.

  Subsequently, the conductor post 40 is opposed to each electrode of the semiconductor elements 10 and 10a.

  Thereafter, the support plate 30 is passed through an H2 reflow furnace (manufactured by Denko) at a speed of 120 mm / min, and the electrodes of the semiconductor elements 10 and 10a and the conductor posts 40 are soldered. When the solder is melted, the maximum temperature achieved by heating is 350 ° C. Moreover, the time heated to 270 degreeC or more is 25 minutes. Then, the soldered substrate is taken out from the reflow furnace at a cooling rate of 100 ° C./min.

  According to such a method, solder fillets are formed on the conductive materials 72 a to 72 d for connecting the conductor posts 40. The solder (conductive materials 72a to 72d) rises to a height of 0.2 mm.

  The electrodes of the semiconductor elements 10 and 10a and the conductor post 40 are connected together (collectively connected) by the above method. Thereafter, the external connection terminals 61 to 65 are connected by soldering according to the above, whereby the semiconductor device 102 is completed.

  According to the semiconductor device 102 of the first embodiment, a large current can be passed as follows.

  In order to measure the allowable current of the semiconductor device 102, the inventor applied the electrode 14 (emitter electrode) of the semiconductor element 10 at a room temperature of 25 ° C. while cooling the lower surface of the heat sink with water of 0.5 m / min and 50 ° C. A current was passed, and the current when the temperature of the semiconductor element 10 reached 150 ° C. was measured. As a result, it was possible to flow 63 A (ampere) per one of the 15 conductor posts 40 included in the emitter post E, that is, a total of 945 A.

(Example 2)
Hereinafter, the semiconductor device 101 according to the second embodiment (see FIGS. 1 and 2) will be described. In this example, the same elements as those shown in the above embodiment are denoted by the same reference numerals, and more detailed parameters are specified for each element.

  Similar to the first embodiment, the semiconductor element 10 is an IGBT chip, and the heat sink 20 is an ALN heat sink.

  The support plate 30 is manufactured by the following procedure.

  First, as shown in FIG. 23A, a starting material for the support plate 30 (hereinafter referred to as a starting substrate 300) is prepared. The starting substrate 300 is Upilex (registered trademark, Ube Industries). The starting substrate 300 includes an insulating substrate 30a and copper foils 301 and 302 laminated on both surfaces of the insulating substrate 30a. The insulating substrate 30a is a polyimide substrate. The thickness of the insulating substrate 30a is 0.05 mm, and the thickness of the copper foils 302 and 302 is 0.17 mm.

  Subsequently, as shown in FIG. 23B, a hole 30b having a diameter of 0.6 mm is formed (drilled) in the starting substrate 300 by a carbon dioxide gas laser. The hole 30b is a through hole. The hole 30b is formed to face each of the electrodes 12 to 14 (pads). The number of holes 30b facing each electrode is the same as in the first embodiment.

  Subsequently, as shown in FIG. 23C, a chemical copper plating film 303 having a thickness of 0.1 μm is formed on the entire substrate surface by chemical copper plating (manufactured by Uemura Plating).

  Subsequently, as shown in FIG. 23D, an electrolytic copper plating film 304 having a thickness of 40 μm is formed on the entire surface of the substrate by electrolytic copper plating (Okuno Pharmaceutical Co., Ltd.). As a result, a conductor layer composed of three layers of copper foils 301 and 302, a chemical copper plating film 303, and an electrolytic copper plating film 304 is formed on both surfaces of the substrate, and a conductor 33 (copper plating film) is formed in the hole 30b. The

  Subsequently, as shown in FIG. 23E, the conductor circuits 31 and 32 are formed by patterning the conductor layers formed on both sides of the substrate, as in the first embodiment.

  In this embodiment, as shown in FIG. 26A, an electroless nickel film 34 containing 5 μm thick and 1% boron is formed on the surfaces of the conductor circuits 31 and 32 by nickel plating. Subsequently, as shown in FIG. 26B, an electroless gold plating film 35 having a thickness of 0.15 μm is formed on the electroless nickel film 34 by gold plating. Thereby, a coating film composed of two layers of the electroless nickel film 34 and the electroless gold plating film 35 is formed.

  Subsequently, the substrate on which the coating film is formed is cut into a size of 14 × 12 mm. A dicing saw (manufactured by Tokyo Seimitsu Co., Ltd.) is used for this cutting. Thereby, the support plate 30 having a thickness of 0.45 mm is obtained.

  The conductor post 40 is manufactured as follows. In addition, the surface of the conductor post 40 according to the present embodiment is coated (see FIG. 10).

  First, a copper wire having a diameter of 0.45 mm is prepared. The copper wire is made of oxygen-free copper C1020 (manufactured by Mitsubishi Shindoh Co.). Then, using a mold, the copper wire is processed by drawing to form a shape as shown in FIGS. 22A and 22B. Thereby, the columnar conductor 40a made of copper is formed.

  After that, the coating film 40b is formed on the surface of the columnar conductor 40a in the same manner as the coating film on the surface of the conductor circuits 31 and 32. That is, the coating film 40b consists of two layers, an electroless nickel film and an electroless gold plating film. As a result, the conductor post 40 is completed.

  The conductor post 40 thus obtained has a shape as shown in FIGS. 22A and 22B. The end face shape (X-Y plane) of the first post 41a side of the conductor post 40, in particular, the part fitted to the hole 30b (hereinafter referred to as the fitting part) is a cosmos shape. The shorter width of the cosmos shape (d1 in FIG. 22A) is 0.54 mm, and the longer width of the cosmos shape (d2 in FIG. 22A) is 0.57 mm. The fitting portion is composed of eight valves (small pieces), and the width of one small piece (d3 in FIG. 22A) is 0.14 mm. The thickness of the fitting portion (d4 in FIG. 22B) is 0.25 mm. The cross-sectional shape of the collar portion 43 is a circle having a diameter of 0.75 mm.

  The conductor post 40 is inserted (inserted) into the support plate 30 as follows.

  First, the conductor post 40 is opposed to the hole 30b of the support plate 30, and both are brought into close contact with each other. Subsequently, the fitting portion of the conductor post 40 is driven into the hole 30b of the support plate 30 with a force of 35 N / piece. Accordingly, as shown in FIG. 21B, the conductor post 40 penetrates the hole 30b and protrudes about 0.8 mm toward the opposite side (arrow Z1 side). Each parameter of the protruding portion of the conductor post 40 (protruding portion P2 in FIG. 21B) is “average diameter: 0.45 mm, average protruding amount: 0.802 mm, aspect ratio: 1.34”.

In this embodiment, the conductor post 40 is inserted (inserted) into the hole 30b of the support plate 30 from the first end 41a side. Thereby, the wall surface (more specifically, the conductor 33) of the hole 30b is pressed by the conductor post 40 and deformed. As a result, the conductor post 40 is fixed in a state of being engaged with the conductor 33. The fitting area (fixed area) was 0.308 mm ² . The side surface S2 (circumferential surface) of the conductor post 40 and the side surfaces of the conductor circuits 31 and 32 are substantially in contact with each other. This contact area was 0.258 mm ² . This corresponds to 37.4% of the side surface S2.

  With this method, the conductor posts 40 are inserted (inserted) into all the holes 30b. As a result, the coplanarity of the conductor post 40 was 0.013 mm.

  Thereafter, the semiconductor element 101 is completed by connecting the semiconductor element 10 to each of the heat sink 20 and the connection substrate 50 and connecting the external connection terminals 61 to 64 by soldering.

  According to the semiconductor device 101 of the second embodiment, a large current can be passed as follows.

  As a result of measuring the allowable current of the semiconductor device 101 by the inventor in the same manner as in the first embodiment, 57 A (ampere) per one of the 15 conductor posts 40 included in the emitter post E, that is, a total of 855 A is passed. I was able to.

(Other examples)
Further, an example in which the material of the conductor post 40 in Example 1 is changed (Example 3) and an example in which the insertion amount and the fixing area of the conductor post 40 in Example 1 are changed (Examples 4 and 5) are allowable. Current etc. were measured. Moreover, the example (Example 6, comparative example 1) which changed the end surface dimension (fitting dimension) of the conductor post 40 in Example 2, the example which did not use a solder ball for the connection of the conductor post 40 and the hole 30b Regarding (Example 7), the allowable current and the like were also measured. These results are shown in FIGS. 27 to 30 together with the results of Examples 1 and 2 above. In the figure, samples # 11 to # 17 correspond to the semiconductor devices of Examples 1 to 7, and sample # 21 corresponds to the semiconductor device of Comparative Example 1. FIG. 27 shows the shapes of the holes 30b and the conductors 33. In FIG. 28, the material etc. of the conductor post 40 are shown. FIG. 29 shows the fixing area (fitting area) of the fixing part. FIG. 30 shows the measurement result of the allowable current.

  In addition, the material of the conductor post 40 in Example 3 (# 13) is pure aluminum 1N99 (manufactured by Sumitomo Light Metal Co., Ltd.). Further, in Examples 4 and 5 (# 14, # 15), the fixing area was changed by setting the insertion amount of the conductor post 40 to 0.3 mm and 0.7 mm.

  As shown in FIG. 30, in Samples # 11 to # 17 (Examples 1 to 7), the allowable current is larger than that of Sample # 21 (Comparative Example 1).

  The above embodiments and other examples can be combined.

  The embodiment of the present invention has been described above. However, various modifications and combinations required for design reasons and other factors are not limited to the invention described in the “claims” or the “mode for carrying out the invention”. It should be understood that it is included in the scope of the invention corresponding to the specific examples described in the above.

  The semiconductor device according to the present invention is suitable for a power device that requires a large current to flow. The method for manufacturing a semiconductor device according to the present invention is suitable for manufacturing such a semiconductor device.

10 Semiconductor device (IGBT chip)
10a Semiconductor device (FWD chip)
11-14 Electrode 11a, 12a Electrode 20 Heat sink 21 Electrode 30 Support plate 30a Insulating substrate 30b Hole 31, 32 Conductor circuit 33 Conductor 34 Electroless nickel film 35 Electroless gold plating film 40 Conductor post 40a Columnar conductor 40b Coating film 41 First 1 pillar part 41a 1st edge part 42 2nd pillar part 42a 2nd edge part 43 collar part 50 connection board 61-65 external connection terminal 71a-71c, 72a-72d, 73a-73d, 74 conductive material 74 conductive material 101, 102 Semiconductor device 300 Starting substrate 301, 302 Copper foil 303 Chemical copper plating film 304 Electrolytic copper plating film 401 Copper plate 1001 Mold punch 1002 Mold die E Emitter post F FWD post G Gate post S Sensor post

Claims (11)

A cylindrical hole is formed, and a support plate having a conductor formed on the wall surface of the hole;
A power semiconductor element;
A conductor post comprising a columnar conductor having a first end at one end and a second end at the other end;
With
The end face shape of the first end portion and the opening shape of the hole are in a similar relationship,
The fixing surface between the side surface of the conductor post and the conductor of the hole wall surface includes two or more surfaces having substantially the same area, and these surfaces are arranged substantially symmetrically,
The second end of the conductor post is connected to the power semiconductor element;
The side surface of the conductor posts, in the first end portion side of the second end portion is partly fixed to the conductor of the hole wall is deformed by the pressing of the conductor posts,
A semiconductor device. The contact area between the conductor post and the conductor on the hole wall surface is at least 50% or more of the area of a cross section perpendicular to the axial direction of the conductor post.
The semiconductor device according to claim 1. A conductor layer is formed on at least one main surface of the support plate,
The side surface of the conductor post is in contact with the conductor layer of the main surface;
The semiconductor device according to claim 1, wherein: The contact area between the side surface of the conductor post and the conductor layer is at least 15% or more of the area of a cross section perpendicular to the axial direction of the conductor post.
The semiconductor device according to claim 3. The end face shape of the first end, yen elliptic, rectangular, regular polygon, positive polygonal star, cross, cosmos form, or a combined shape of two or more thereof,
The semiconductor device according to any one of claims 1 to 4, characterized in that. The main component of the conductor post is copper, silver, gold, or aluminum.
The semiconductor device according to any one of claims 1 to 5, characterized in that. The conductor post is
Columnar conductors based on copper, silver, gold, or aluminum;
A coating film made of chromium, nickel, palladium, titanium, or platinum formed on the surface of the columnar conductor;
Having
The semiconductor device according to any one of claims 1 to 6, characterized in that. The coating film has a thickness of 0.5 μm to 10 μm.
The semiconductor device according to claim 7 . The semiconductor device further includes a heat dissipation plate having a conductor layer on at least the support plate side main surface,
At least one electrode of the power semiconductor element is fixed to the conductor layer of the heat sink;
The semiconductor device according to any one of claims 1 to 8, characterized in that. Forming a cylindrical hole in the support plate;
Forming a conductor on the wall of the hole;
A first end of a conductor post having an end face shape dissimilar to the opening shape of the hole is fitted into the hole, and the first end and the conductor on the hole wall surface are partially fixed; ,
Connecting a second end of the conductor post opposite to the first end to a power semiconductor element;
Only including,
The fixing surface between the side surface of the conductor post and the conductor of the hole wall surface includes two or more surfaces having substantially the same area, and these surfaces are disposed substantially symmetrically.
A method for manufacturing a semiconductor device. The width of the first end portion of the prefrontal Symbol fitting is different from the corresponding portion of the width of the hole is greater by 5% to 75% of the dimensions of the conductor thickness of the hole wall,
The method of manufacturing a semiconductor device according to claim 10 .

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